This invention relates to an ultrasonic horn for use in manufacturing operations such as bonding, perforation, and cutting. More specifically the invention relates to an ultrasonic horn that includes an integral isolation member.
Ultrasonic horns are used to distribute ultrasonic energy in a variety of industrial processes. One example involves bonding of two thermoplastic sheets of material together in the manufacture of personal care products such as diapers.
Ultrasonic horn systems can have a number of distinct components, which can be connected in a stack. In one arrangement, these components may include a power excitation device known as a converter (or driver assembly), amplitude modification devices known as boosters, and an ultrasonically energized tool known as an ultrasonic horn, at least a portion of which imparts ultrasonic energy to a work piece. In addition, the ultrasonic horn can include isolation members that can be configured for mounting the horn at a work (i.e., bonding) location.
Generally, horns have been manufactured by machining a final horn shape from forged bar stock, such as titanium bar stock. Alternatively, horns can be manufactured by way of machining the horn from a hot isostatically pressed preform for improved performance.
Unfortunately, in certain circumstances, such horns may not always be completely satisfactory. For example, even in the case of hot isostatic pressing, machining the horn from the base piece of material can result in a certain amount of potentially costly material that must be machined into the desired shape. Moreover, since the ultrasonic horn is typically manufactured from a material that can transport or transmit ultrasonic energy in a highly efficient manner, isolation members that are also of that same material may not function completely as desired. In particular, the isolation member in such circumstances may be more susceptible to higher noise transmission and potentially undesirably heating of the mounting element that it is joined to (e.g., a bearing).
Thus there is a need for an ultrasonic horn that is provided by a material that efficiently transports ultrasonic energy but yet includes an isolation member that is at least partially of a different material, suitably a material that is less efficient at transporting ultrasonic energy. In addition, there is a need for an ultrasonic horn that can be provided by a method that results in an effective ultrasonic horn but with reduced material waste.